[PATCH v4 04/11] swiotlb: support NOT_COHERENT_CACHE PowerPC platforms

[FUJITA Tomonori]

On Fri, 12 Mar 2010 20:12:39 +0100
Albert Herranz <albert_herranz at yahoo.es> wrote:

> The current SWIOTLB code does not support NOT_COHERENT_CACHE platforms.
> This patch adds support for NOT_COHERENT_CACHE platforms to SWIOTLB by
> adding two platform specific functions swiotlb_dma_sync_page() and
> swiotlb_dma_sync() which can be used to explicitly manage cache coherency.
> 
> On PowerPC these functions are mapped to their corresponding
> __dma_sync_page() and __dma_sync() functions.
> On other architectures using SWIOTLB these functions are optimized out.
> 
> This will be used later to support SWIOTLB on the Nintendo Wii video game
> console.
> 
> CC: linuxppc-dev at lists.ozlabs.org
> CC: linux-kernel at vger.kernel.org
> CC: x86 at kernel.org
> CC: linux-ia64 at vger.kernel.org
> Signed-off-by: Albert Herranz <albert_herranz at yahoo.es>
> ---
>  arch/ia64/include/asm/swiotlb.h    |   10 ++++++++++
>  arch/powerpc/include/asm/swiotlb.h |    3 +++
>  arch/x86/include/asm/swiotlb.h     |   10 ++++++++++
>  lib/swiotlb.c                      |   30 ++++++++++++++++++++++++------
>  4 files changed, 47 insertions(+), 6 deletions(-)

Why can't you use dma_sync_single_* instead of inventing new
swiotlb sync functions?